It was the third attempt to get the charges against Slipper thrown out.

Slipper's lawyer Kylie Weston-Scheuber told the court the prosecution failed to prove that her client was not on parliamentary business because there was no legal definition of the term.

But prosecutor Lionel Robberds told the court the trips were clearly not parliamentary business and Slipper had filled in multiple travel vouchers in a bid to hide the fact.

The taxi driver also told the court Slipper asked for four vouchers, telling him it was easier to process that way.

Peter Slipper visited wineries 'well beyond Canberra boundaries'

Chief Magistrate Lorraine Walker dismissed the application and said based on evidence so far a tribunal could be satisfied beyond reasonable doubt the defendant had caused a risk of loss to the Commonwealth.

She went on to say a tribunal could also be satisfied that he had done so knowingly.

She said it was significant that although the wineries Slipper visited were well beyond the boundaries of Canberra, they were described by him on the Cabcharge vouchers as suburbs.

Ms Walker told the court, that if parliamentary business was coincidentally conducted during travel, it did not mean the travel was on parliamentary business.

"The overwhelming inference must be this travel to the wineries was for the purpose of what one usually does at wineries," she said.

Slipper good as his word: character witness

After the Chief Magistrate's decision that the hearing would continue, Slipper's defence team called two character witnesses who lived in Adelaide to give evidence via videolink.

Retired archbishop of the Traditional Anglican Church in Australia John Hepworth and Catholic Priest Reverend John Fleming testified that they knew Slipper well from his extensive church involvement.

Archbishop Hepworth said he had first met Slipper in the early 1990s at church gatherings and conferences and later oversaw his ordination into the priesthood.

"He was honest in his dealings with me and the church," he said.

Archbishop Hepworth said Slipper had also provided him advice on church matters.

"His advice was to be scrupulous, his advice was not to cut corners," he said.

Father Fleming, who had known Slipper since 2004, told the court Slipper had always been "as good as his word" and a generous man who would not knowingly take from others or steal.

'A bit unusual' is not enough

During closing submissions on Thursday, Mr Robberds pointed to the Chief Magistrate's earlier finding that a tribunal could be satisfied Slipper knowingly caused a risk of loss to the Commonwealth.

"There's no good reason why you should not make those findings again having considered all the evidence," he said.

"He (Slipper) was having a good time on these trips, and it had nothing to do with parliamentary business."

But the defence said the prosecution had failed to prove its case.

"The prosecution must prove that what he did on each occasion was dishonest," Ms Weston-Scheuber said.

"The fact that somebody does something that is a bit unusual might perhaps lead to an inference of dishonesty, but there's got to be a reason why it's dishonest as opposed to a little bit unusual.

"In my submission, when one considers all the evidence together, the evidence about what slipper did on each of these occasions is not evidence of dishonesty."

Chief Magistrate Walker indicated she intended to finalise the matter next week.